Note that in the schematic above this is a PNP positive ground device. The original transistors were silicon devices, I think that I have sourced some from somewhere and they are nothing particularly special. Below is my stripboard layout for the Wah which I have converted to NPN - negative ground. Usual suspects work in this: BC108, 2N3904 etc. The original layout is smaller, but the parts are all over the place, I've built working devices from my layout. Substitute the old values with nearest value you can find and it should be fine. Black squares equal track cuts.

kaycee wrote:I ended up with BC108's in mine I think? Still not boxed up yet, thinking about adding the Foxxrox's wah buffer to it. Soundwise its similar to the Colorsound inductorless wahs.

Mictester, you mention a 470 ohm in your text, but I don't see it on the layout?

I missed it off that diagram! Sorry Just add a 470 ohm between the PCB and the Battery +. With the extra 100µF across the rails, it helps a lot. I also added the usual 1N4001 "idiot diode", reverse biased across the supply rails to prevent damage in the event of the wrong polarity adaptor being plugged in. I used a 1/8th Watt 470 ohm resistor, which would vapourise if the "idiot diode" conducted!

Corrected diagram (I missed one link and the 470 ohm resistor):

Wilsic.png

This circuit is worth experimenting with - you can "tune" the range of frequencies covered, and alter the shape of the resonant peak. I'll leave these modifications for the class to work out for themselves.....!

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kaycee wrote:I ended up with BC108's in mine I think? Still not boxed up yet, thinking about adding the Foxxrox's wah buffer to it. Soundwise its similar to the Colorsound inductorless wahs.

Mictester, you mention a 470 ohm in your text, but I don't see it on the layout?

I missed it off that diagram! Sorry Just add a 470 ohm between the PCB and the Battery +. With the extra 100µF across the rails, it helps a lot. I also added the usual 1N4001 "idiot diode", reverse biased across the supply rails to prevent damage in the event of the wrong polarity adaptor being plugged in. I used a 1/8th Watt 470 ohm resistor, which would vapourise if the "idiot diode" conducted!

Corrected diagram (I missed one link and the 470 ohm resistor):

Wilsic.png

This circuit is worth experimenting with - you can "tune" the range of frequencies covered, and alter the shape of the resonant peak. I'll leave these modifications for the class to work out for themselves.....!

Hi Mictester

Doe the additional 100uf go from D14 to E14? Or is that simply another jumper.Also will the 470k resistor be needed if i am running from a 9V power supply.

The 100uF capacitor is C8 on the layout, and D14 - E14 is just a jumper.

The extra resistor is 470 ohms (NOT 470k!!). It reduces the current consumprtion of the circuit a little, but more importantly, it cleans up the +9V supply rail. It makes the circuit less susceptible to hum and lowers the noise a little.

I just built one of these earlier today. The Vero layout is a bit different because it's got a Fuzz on the same board (it's a Fuzz-Wah for a friend), and it sounds great. Unfortunately, I've just broken the pedal mechanism, and I've got to go to work in 15 minutes, so it'll have to wait until tomorrow to get the mechanism mended and the thing fully tested.

I'll draw up a neatened version of the Vero tomorrow, and post it here.